For all the drama — and melodrama — that Donald Trump and Hillary Clinton have brought to this election, are they merely bobbing about on the currents of history? Is it all just a case of America going through the 24-year itch?

That’s the phrase of a historian named Paul Rahe. Normally he focuses on ancient Greece and Western civilization. So he tends to take the long view of things, and he offers a refreshing context for all the quarreling between Clinton and Trump.

It was, he points out, 24 years ago that Ross Perot launched his campaign for president on a populist wave of disgust at government. The result was that he toppled President George H.W. Bush and handed the presidency to Bill Clinton.

Twenty-four years before that, Rahe notes, the segregationist ex-governor of Alabama, George Wallace, broke from the Democrats and ran for president as head of a third party. By his own account, he hoped to force the presidential election into the House of Representatives.

Wallace failed, but his rebellion against busing to integrate schools, his vow to win in Vietnam or end the war and his campaign that sought to defend blue-collar workers from the machinations of pointy-headed intellectuals had an effect, helping to move many Southern Democrats to the GOP.

It’s not Rahe’s purpose, in pressing his theory of the itch, to belittle Trump’s overthrow of the Republican Party leadership. Or to disparage the revolt that Bernie Sanders led and lost within the Democrats.

Rahe’s point — he told me in a phone conversation this week — is that these rebellions are part of “the rhythm of politics in a liberal, representative government.” This, he says, goes back at least to the American founding in 1776.

Twenty-four years after that, in 1800, the itch erupted. That’s when the Federalists of George Washington, by then gone, and John Adams were toppled by the populists led by Thomas Jefferson, giving rise to what would eventually become the Democratic Party.

Exactly 24 years later, the itch hit big time, with the rise of Andrew Jackson. He threw the election of 1824 into the House, where John Quincy Adams beat him despite winning just 39 percent of the popular vote.

Jackson finally prevailed in 1828. Backed by a wave of populist support, he had a transformative presidency. He fought against the big banks and fixed the trajectory for the modern Democratic Party.

“Disturbing parallels” between Trump and Jackson have been drawn by the History News Network, which says both have been called “dangerously abrasive” and “arrogant.” And also for their appeal to “common-man voters who feel threatened by change.”

Rahe reckons that the 24-year itch struck again in 1852, with the Whigs, who’d emerged in opposition to Jackson. And the itch was at work in 1876, when Democrat Samuel Tilden beat Rutherford Hayes in the popular vote but lost the presidency.

That happened with a famous compromise, in which the Democrats agreed to give up some 20 unresolved votes in the Electoral College in exchange for a promise from the Republicans to end Reconstruction in the South.

Then in 1896 came a historic populist surge, led by Nebraska Democrat William Jennings Bryan. He stirred up Western voters against big-money centers but got trounced by Republican William McKinley.

Twenty-four years later, Republicans Warren Harding and Calvin Coolidge, in the greatest American landslide, ended the Progressive Era and opened the Roaring Twenties. Twenty-six years later, the GOP roared to power in Congress, soon to be followed by Dwight Eisenhower.

It’s certainly possible to quibble over the details of the timeline of the 24-year itch. Not even Professor Rahe suggests the theory means Trump is going to score a surprise victory.

Rahe does, however, think that the itch that’s beset our current campaign is, as he put it to me, “bigger than it has ever been before.” The sign of that, he says, is that “it’s happened in both political parties” — a reference to Sanders.

There is “a moral to the story,” Rahe has written: When politicians “step on” voters, “they get spitting-mad” and “you had better watch out.” The party that addresses their concerns, he predicts, “will prosper mightily” — even for another 24 years.